<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        .box{
            width: 1000px;
            margin:100px auto;
        }

        .box>div{
            width: 300px;
            height:150px;
            border: 1px solid #000;
            background-color: red;
            float: left;
            margin-right: 30px;
        }

        div:nth-child(2){
            background-color: pink;
            transition:all 1s;
        }

        div:nth-child(2):hover{
            /*width: 600px;*/
            /* 变形*/
            /*
                scale: 缩放
                scale(水平放缩比例，垂直放缩比例)；
                大于1：放大
                小于1：缩小
                如果只写一个值等比例缩放
            */
            transform: scale(2,0.5);
        }
    </style>

</head>
<body>
<div class="box">
    <div class="box1">1</div>
    <div class="box2">2</div>
    <div class="box3">3</div>
</div>

</body>
</html>